(Foreword)

Pull out the cocoon, the mystery of the code.

(Text)

December 5, 2021 at 10:30 a.m

"A password is a technique used to obfuscate people who want to turn normal (identifiable) information into unrecognizable information. Of course, for a small group of people, this unidentifiable information can be reprocessed and recovered. Password is a common term for "passord" in Chinese. It is mainly limited to a system of symbols that are understood by an individual person (e.g. a message). Such as cipher telegram, cipher typewriter ......"

The lecturer of information science on the podium was talking, and I was drowsy.

"Don't fall asleep, it's an interesting lecture. I was worried that there would be a lot of people and I wouldn't be able to find a seat, but luckily we came early. ”

"Yes......" I replied perfunctorily to Li Ruina's words, and continued to support my head with one hand, my eyelids almost closed. We came early enough, it was clearly a 10 a.m. lecture, but Li Rena asked me to arrive at 8 o'clock, and if she hadn't helped me at the amusement park, I wouldn't have bothered to come with her to listen to this boring lecture. It's rare that the school gave me a long vacation, but I still came to the school to listen to the lecture. And almost all of the people sitting here are students, and the lecture is just a lecturer who doesn't look very old. It seems that there won't be any information related to 'Z'' teaching.

The lecturer on the podium is still talking about the composition of the password, and some of the students sitting in the audience have begun to pack their schoolbags and prepare to leave, it seems that this lecture is not so interesting to Li Ruina, but whether it is interesting or not, it is the same for me, anyway, I don't understand.

Forget it, just come out once in a while to get some fresh air.

The corners of my mouth lifted and I slowly closed my eyes.

December 5, 2021 at 12:00 p.m

"Jingle bell~~Jingle bell~~" With the ringing of the bell after class, the students sorted out the materials and got up to leave. And I was awakened.

"What's class?" I asked, "How's it going?" ”

"There's nothing to gain, and she only talked about some fundamentals, just scratching the surface, which seems to make me happy." Li Ruina shook her head and let out a long sigh.

"Ah~~~" I covered my mouth and yawned, supported my head with my hands and asked Li Ruina, "Didn't you just say that this speech was very interesting?" Why, after only a short period of effort, I feel bored? ”

Li Ruina glared at me and explained: "I was just fooled by her introduction at the beginning, and mistakenly thought that she was a master of studying passwords. It just wasted a morning of my time. ”

"Oh? So, you're pretty good at cryptography? ”

"Well, apart from artificial intelligence, I'm most interested in software programming and cryptography. Especially in cryptography, there is almost no one above me except Miss Gu. ”

"You're exaggerating, aren't you? So what is a password? I asked earnestly to Li Ruina.

"A password is a symbol that is coded according to a specific law to transform the information between the two sides of the communication. In other words, a password is a sequence of symbols that conceals the real content. It is to transform the information expressed in the open and standard information code into an information code that cannot be read by anyone other than the two parties to the communication, and this unique information code is the password. ”

"Well, that sounds like that. But it's just some theoretical knowledge, nothing special, can't it be from the lesson just now? I asked rhetorically.

"You don't believe it? Then if you have any questions, just ask, let you see what I really can. "Li Ruina really moved, and she actually got into a fight with me.

"This one still counts...... I don't really understand ...... "I just wanted to decline Li Ruina's proposal, but suddenly I realized something-Miss Gu?"

Why do I have a sense of intimacy with the name, wait, isn't it......

"Li Ruina, who do you say Miss Gu is?" I asked eagerly.

"Why, aren't you not interested? If I just say her name, you may not know her. Li Ruina said disdainfully.

"Li Ruina, is it possible that the Miss Gu you mentioned earlier refers to Gu Xiaohe, Miss Gu?" I asked, this answer is important to me.

“XiaoHe Gu？ Gu Xiaohe? That's right, it's her, do you know her? Li Ruina was surprised.

Yes, I do, not only do I know, but I'm also her son. But I can't tell Li Rena about all this.

"Yes, I do know her, and I've had a few encounters with her." At this point, I paused, took out the phone left by the 'queen' from my pocket, hesitated for three seconds, and then placed the red phone in front of Li Ruina.

"Since you want me to take the test, why don't you help me unlock this phone. I just forgot the password to start. ”

Li Ruina glanced at me, "Okay, so I can also show you my strength." In this case, I will leave this phone with me first, and I will return it to you the next time I see you. ”

I deliberately feigned disbelief: "Do you want to take it back?" I think you can't solve it, so you want to take it back and let others help. ”

"What do you say! I won't be able to untie this phone? You underestimate people, don't forget that I'm the chief engineer of AEF. Li Rena retorted.

"Okay, okay, I said the wrong thing, but this phone is really important to me, can you unravel it now?" I said sincerely.

Li Ruina looked around, "Okay, everyone here is almost gone, let's go somewhere else, sit down, and untie this mobile phone with determination." ”

I nodded in agreement, got up and walked out of the classroom door with Li Ruina.

December 5, 2021 at 1:28 p.m

Li Ruina saw a pastry afternoon tea restaurant at a glance. The restaurant looks luxurious, with a one-to-one model of a pumpkin carriage and a snow-white unicorn with a brick clearly visible through the transparent glass.

I, swallowing a mouthful of saliva, sneaked into my pocket. Sometimes it's worth it to save the world!

"Shall we go in?" Li Ruina said without seeing it.

"Good...... All right. ”

After I entered the door, I chose to sit on a swing chair and respectfully placed my phone in front of Li Ruina.

"There's no hurry, why don't we order something to eat first?" Li Ruina glanced at the menu on the side.

I really don't know if Li Ruina came here to eat or came here to unlock the password. But seeing that she is so confident, I can only listen to her for the time being.

"Okay, okay. What do you order? ”

I put the menu in front of Li Ruina again, and Li Ruina flipped through a few pages of the menu and ordered several expensive desserts in one go. And I could only silently touch my pocket and cry in my heart.

Soon almost all the desserts on the table were eaten by herself. Watching her eat dessert, to be honest, I was stunned.

"Li Ruina, you have already eaten the dessert, can you help me untie this phone?" I asked.

"What's the hurry, didn't I just finish eating?" Li Ruina looked at my anxious eyes: "Okay, okay, I'll take a look now." ”

She finally brought the "Queen's" red phone to her and pressed the power button.

The screen shows an 8-digit password that requires a set of formulas and combinations, with an exclamation mark in the upper right corner and a number next to the sign.

Li Ruina smiled, propped her head with one hand, and looked me in the eye: "Cheng Yin, your meal is really worth the price, this is not an ordinary mobile phone lock, it is impossible to unlock it for others." But I'm glad you met me. ”

I scratched my head, glanced at Li Rena embarrassedly, and asked in a low voice, "Then can you crack it?" ”

"It's up to people to make things happen, and I'm trying to try. However, the password is very well designed, and I don't necessarily guarantee that it will be opened. ”

I saw Li Ruina press the shutdown button of the mobile phone, then press the volume button again, and press the power button again until the mobile phone automatically entered recovery mode.

"This mode is the background management mode, now let me take a look at the operation in this."

Li Ruina frowned, carefully studied the program code in the mobile phone, and his expression looked serious.

"In order to prevent theft, the user of this mobile phone actually used the Vigenard code to make up a boot lock." Li Ruina said.

I looked at Li Ruina, and I didn't know what she meant by what she said.

December 05, 2021 at 1:50 p.m

"Wait, what kind of password are you talking about? What the hell is this password? I asked.

Li Ruina gently stirred the chocolate milk tea in front of her with a spoon, took a sip, and said slowly: "The Vergenal cipher is a very famous multi-code encryption method (also translated as the "Virginia cipher"), which is actually a simplified form of autokey encryption, which is a keyword-based encryption system. It was invented by the French diplomat Blaise de Vigenère.

With this encryption method, different letters in the same message can be encrypted with different passwords. Thus, the same E may be replaced by M in one position, and E in another position may appear as K. In this way, it is possible to prevent anyone from decrypting the message using frequency analysis. ”

I nodded as if I pretended to understand, and continued, "So what now?" “

Li Ruina raised her head and looked into my eyes, "Do you know the key?" “

"Key?" I asked, puzzled.

"In Vigenère's cipher, the sender and the recipient must use the same keyword (or the same text section) that tells them how to change the position of the letters back and forth to get the correct position of each letter in that message. For example, if the keyword "BIG" is used, the sender will put the messages in three-letter order. The first letter of the first three-letter word should be moved backward by one position (since B is the letter after A), the second letter should be moved back by 8 bits (I is the 8th letter after A), and the third letter should be moved back by 6 bits (G is the 6th letter after A). As she spoke, she took out a pen and a piece of paper from her bag, on which she wrote:

For example

The unencrypted text is: THE BUTCHER THE BAKER AND THE CANDLESTICK MAKER.

The key key is: BIG BIGBIGB IGB IGBIG BIG BIG BIG BIGBIGBIGBI GBIGB

The encrypted text is: UPK CCZDPKS BNF JGLMX BVJ UPK DITETKTBODS SBSKS

And vice versa.

In other words, if you know that "BIG" is the key, you can easily change the position of the letters by the corresponding position to translate the encrypted text. Li Ruina said this, and asked me again, "Do you know the key?" If you don't know the key, it will take a lot of engineering and time to hack this phone. ”

I, with my eyes closed, tried to recall in my mind the scene when the "Queen" blew up the glacier - she threw her phone up and into my arms with the last of her strength. She finally opened her mouth as if to say something to me, but the words were swallowed up in the fire, and in an instant they were obscured by the falling snow and ice.

What did she want to tell me at that time?

My head started to hurt and memories were churning in my head, what was it? I searched for the slightest clue in my mind, and at that moment I seemed to hear a voice, an extremely faint voice, and it seemed as if it had been in my head all along.

“…… June ......"

June?

I opened my eyes suddenly, and the word "June" came to my ears.

"June, you try to enter June!" I said to Li Ruina.

"June? The codes in this are all made up of English letters, where do the Chinese characters come from? Li Ruina asked puzzled.

"That'...... June? Why don't you type June into English? “

Li Ruina glanced at her phone, "Okay, I'll try." ”

I saw Li Ruina deciphering the code of her mobile phone on the paper, pressing here and there on the screen, and constantly typing something.

December 5, 2021 5:39 PM

Before you know it, the sun has set in the west. Outside the pastry shop, people come and go, and the footsteps are hurried. Just as I was looking at the crowd of people coming and going, Li Ruina raised her head suddenly, looked into my eyes with a look of surprise, and said excitedly, "That set of formulas has been lifted by me, and all that is left is this set of 8-digit passwords." Now I'm going to crack this password, but it's time-consuming. Of course, you can also help me to staff and see what I can recall. Next to the password, a prompt popped up, and the prompt read: My most heart-wrenching day. ”

My most heartbreaking day?

The most heart-wrenching day of the "Queen"...... What day was that?

I closed my eyes again, and the memory brought me back to that day, the day she blew up the glacier......

She opened her mouth, and finally smiled with tears in her eyes, her expression was so gentle, it was An Ran I had never seen.

She stretched out her hand to me, and even though she couldn't touch my cheek, I seemed to feel the warmth of the palm, so warm.

The dragon lunged at her, but she shouted to me, "Char, I love you and I love Shaman." If I could, I would have liked not to put you on that ship on the first day of June. Unfortunately, we all have no choice but to do it. “

A line of tears burst out of my eyes and dripped down my wrists.

We all have no choice but to choose......

I clutched the teacup in front of me tightly.

In fact, I obviously heard the last words of the "Queen", but I have been deliberately blocking it and deliberately forgetting it.

The memories of the past made my heart deny the "Queen" and the "Queen's" love for me. All this time, I almost forgot that she was originally a mother, and she had love for her children, but also had pain for her children.

"Cheng Yin, why are you crying?" Li Ruina asked anxiously, handing me a pack of tissues.

I rubbed my eyes and smiled, "It's okay, it's just that there's a worm in front of me that flew into my eyes." ”

"Oh, that's right." Although Li Ruina was slightly skeptical, she still did not pursue the question.

"20500601," I blurted out.

“20500601？“ Li Ruina asked rhetorically.

"Yes, you enter those 8 digits and try it."

Li Ruina paused, and half-doubted entered the eight-digit password. As soon as the password was entered, the mobile phone suddenly entered the main interface.

"It's really these 8 figures!" Li Ruina exclaimed, and then showed a trace of puzzlement, "But the user of this mobile phone is really strange, and the most heart-wrenching day is actually the future 29 years later." “

"yes, that's weird." I casually gave Li Ruina a perfunctory look, but I felt a sharp cramping pain in my heart.

"But this kind of boot lock, I have never seen it on the market. If I weren't familiar with mobile phone programming and password unlocking, I'm afraid I wouldn't have been able to open it if you studied it for another ten years. Li Ruina said proudly.

I retorted, "Not necessarily, the code is what I remembered, and you've just solved a formula at most." ”

"Just a formula? You know, it's hard in this formula! This is a small formula, how much data I need to derive and how much code I need to adapt to completely remove it! Li Ruina said unconvinced.

"Good, good. Thank you. I said respectfully.

But if it weren't for Li Ruina's help, I'm afraid I wouldn't have been able to unlock the password of this mobile phone for a while.

"I'll just take your words as a compliment to me." Li Ruina said proudly.

"You're not modest at all." I said.

"That's, okay, I've helped you unlock your phone, I'll go back first, bye." Li Ruina stood up from the swing and left the door of the dessert shop.

I looked at the 'Queen' mobile phone that was unlocked by Li Ruina in my hand, and I felt a lot of emotion in my heart. I know this phone is so important to me. I looked out the window, tears shining in my eyes.

(End of chapter)